Wow, I am now convinced to *never* buy a Chaintech mobo. If the quality of their manual is any indication, I'd rather not see what problems will actually crop up with their motherboards.
I went to their site, d/led the manual, having never heard of a BIOS that only had a "hard drive" option. It's set up as : HDD0, HDD1, 2, 3 etc. Try highlighting the "hard drive" option and pressing buttons. There should be something at the bottom of the page listing the command buttons for your BIOS. Use this to see if you can change the "hard drive" selection to HDD1, 2, etc or something identifiable as such. But honestly, I've never seen a mobo manual with basically no in depth information about the frickin board. I hope the physical manual you got is better and the online manual is not an indication of their quality.
Also, try getting into different areas of your BIOS, maybe more information you're not seeing